ABSTRACT
The stability and droplet size of protein and lipid stabilised emulsions of caraway essential oil as well as the amount of protein on the emulsion droplets have been investigated. The amount of added protein (beta-lactoglobulin) and lipid (phosphatidylcholine from soybean (sb-PC)) were varied and the results compared with those obtained with emulsions of a purified olive oil. In general, emulsions with triglyceride oil proved to be more stable compared with those made with caraway essential oil as the dispersed phase. However, the stability of the emulsions can be improved considerably by adding sb-PC. An increase in the protein concentration also promoted emulsion stability. We will also present how ellipsometry can be used to study the adsorption of the lipid from the oil and the protein from the aqueous phase at the oil-water interface. Independently of the used concentration, close to monolayer coverage of sb-PC was observed at the caraway oil-aqueous interface. On the other hand, at the olive oil-aqueous interface, the presence of only a small amount of sb-PC lead to an exponential increase of the layer thickness with time beyond monolayer coverage. The amounts of beta-lactoglobulin adsorbed at the caraway oil-aqueous interface and at the olive oil-aqueous interface were similar, corresponding roughly to a protein monolayer coverage.
ABSTRACT
The essential oils from leaves and flowers of costmary, Balsamita major (L.) Desf. (syn. Chrysanthemum balsamita L.), were analyzed at various phases of plant growth. The highest contents of oil both in leaves and in flowers were determined before full blooming, 1.15 and 1.34% (w/w), respectively. Seventy-eight volatile compounds have been identified in the oils of Balsamita major, of which 58 (19 tentatively, 39 positively) have not been reported in this plant previously. Carvone and alpha-thujone were found to be dominating compounds constituting from 51.8 to 68.0% and from 9.0 to 16.1% in the total oil, respectively. Seasonal variations in the oil compositions were not considerable except for the starting phase (May 25, 1995), when the content of carvone was lower and the content of alpha-thujone and sesquiterpenes higher. The content of sesquiterpenes was approximately 2 times higher in flowers than in the leaves. Absolute amount of most components was highest at the bud formation period.
Subject(s)
Food Additives , Oils, Volatile/analysis , Plant Development , Plant Oils/analysis , Plant Leaves/chemistry , Plant Leaves/growth & development , Plant Stems/chemistry , Plant Stems/growth & development , Plants/chemistryABSTRACT
Volatiles of five different parts of lovage (leaves, stems, flowers, seeds, and roots) were isolated by dynamic headspace (DHS) method and analyzed by GC-FID and GC-olfactometry (GC-O) techniques. In total, 98 compounds were identified in the samples, of which 41 are reported as lovage volatiles for the first time. Qualitative differences in the composition of DHS constituents of various anatomical parts of the plants were not significant, whereas the amounts of a number of identified volatile compounds were different in leaves, stems, flowers, seeds, and roots. Seasonal variations in the composition of headspace volatiles were also determined. Except for roots, beta-phellandrene was found to be the most abundant headspace component in all anatomical parts of lovage constituting from 36.50% to 79.28% of the total GC peak area. The sniffing panel characterized effluents from the GC column, and odor descriptors were attributed to the recognized constituents. alpha-Pinene and alpha-phellandrene/myrcene were the most frequently recognized constituents among 11 GC effluents constituting 12 identified compounds and 1 unknown compound, which were detected by the members of the sniffing panel. None of the detected constituents was recognized as a lovage character impact aroma compound.